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We present the detection of a low surface-brightness stellar counterpart to an enormous (190 kpc) ring of neutral hydrogen (HI)
gas that surrounds the nearby radio galaxy B2 0648+27. This system is currently in an evolutionary stage between major merger and
(radio-loud) early-type galaxy. In a previous paper we investigated in detail the timescales between merger, starburst and AGN activity
in B2 0648+27, based on its unusual multi-wavelength properties (large-scale HI ring, dominating post-starburst stellar population
and infra-red luminosity). In this Research Note we present deep optical B- and V-band imaging that provides further evidence for the
merger origin of B2 0648+27. The host galaxy shows a distorted optical morphology and a broad tidal arm is clearly present. A low
surface-brightness stellar tail or partial ring curls around more than half the host galaxy at a distance of up to 55 kpc from the centre
of the galaxy, following the large-scale, ring-like HI structure that we detected previously around this system. The gas and stars in
this ring are most likely tidally expelled material that slowly fell back onto the host galaxy after the merger event. There also appear
to be sites of star formation within the HI ring that may have formed within the gaseous tidal debris after the merger. We argue that
the observed properties of the gas and stars in B2 0648+27, as well as the apparent time-delay between the merger and the starburst
event, may be the logical result of a merger between two gas-rich disk galaxies with a prominent bulge, or of a merger between an
elliptical and a gas-rich spiral galaxy. There also appears to be a significant time-delay between the merger/starburst event and the
current episode of radio-AGN activity.

We present new observational results that conclude that the nearby radio galaxy B2 0722+30 is one of the very few known disc galaxies in the low–redshift Universe that host a classical double–lobed radio source. In this ...

n important aspect of solving the long-standing question as to what triggers various types of active galactic nuclei (AGN) involves a thorough understanding of the overall properties and formation history of their host ...